Apparatus for pumping wells



1954 L. E. ELKINS ET AL APPARATUS FOR PUMPING WELLS 2 Sheets-Sheet l vFiled May 7, 1952 INVENTORS ATTORNEY FIG. 1

Feb. 23, 1954 E. ELKINS ET AL 2,669,936

APPARATUS FOR PUMPING WELLS v Filed May 7, 1952 N 2 Sheets-Sheet 2 I 1IO\ l f FIG. 5 1i 2s g i'r N FIG. 8 j i I a I7LB |9 U L g 1 I6 1 r ILLOYD E. ELKINS RENIC P. VINCENT 1 HENRY SCHAEFER I INVENTORS FIG. 2

ATTORNEY Patented Feb. 23, 1954 APPARATUS FOR PUMPING .w Ls

Lloyd Elkins,. ;Renic P. Vincent, and Henry Schaefer; Tulsa; Okla.,assignorswto stanolind- OiLand Gas, Company, Tulsa, Okla, aicorporaru;ion o l-De aware AP HQ i9 MeYF l'lria Nos 28-6516:

Figure 4 isa cross-sectionalview of -the plungershown in Figure-3having; the skirt portion of 13116; plungerncompressewto the sameoutside d-imenw sions as the solid headportion Figure-5' is across-sectional view taken= -on-= line 5--'-5' of Figure 4 showing theskirt portion :of- If the plunger-in its deformed position as :it wouldmA system-ofthistype-is disclosed in U. S. Patent 1,932,496"'Wellensiek-.a copending application, United states application; Serial Numben261;714 Vincent'filed-December- 14, 1951, variousimprovements v in the:We1lensieksystem have beeni proposed-'wherebythe lifting gas/oil: ratioof suclm-ipu-mping systems may: be materially decreased-.1 Intheimproved: method and apparatust the a power tubing string is Itemporarily-- pluggedcat theloottom onceeach' cycle so that the gasremainingcin the-.power-tubingafter the well fluids havelbeendischargedfro'm the production tubing: is inotirwasteds That is,- in:this improvement; onlytabouthalf of the gasin the system after. a slug.of lwelltfiuids is produced-"is wasted. Biithismeans the pressurein-theproduction tubingcis periodically'reduced'. to substantially'atmospheric pressure, thereby' facilitating the flow of r wellfluiclstinto..-.the.. production tubing. without; at thesame; time,unnecessarilywasting gas;

It-ris an ,objecti'of zthist invention to provide an.

improvement; in, thescycling. 1 gas ilift g plunger or freespistonsystemsby Which-the capacity ofsuch l systems can be increased;particularly where-ai well isgequipped witha smallsizeacasing: It is a,1

more aspecific; objectof .thistinvention to provide.

an ;improvedxcyclinggas lift plunger-nsystem in,-

which the quantity of gaszin thegasaccumulation chamber: or power tubingcana be; varied: overma;

wider-range.

It; is .;still 2 a more; specific: object-10f this. in vention toprgw-ideain,a,,cycling ;gaszliftc; plunger system, power, tubing;'andzproductionq tubing, strings-of different-sizes ;and ;to-,.prov ide,a

ycl n gas lift plunger-which will operatein power tubing and productiontubing 1 strings of; diflierent size. invention'will become'apparentfrom the following description;v Inthis descriptionrefez ence will bemade to thelaccompanying; drawings in which:

Figure 1 isof a cross-sectional view of wellhead apparatus suitableforusein the herein-described cycling gaslift plunger system;

Figure 2. is across-sectional view of that part of the apparatus locatedinvthe Well which isused. inthis system;

Fi ure. 3 isa cross sectional viewpiatypigal These and other 1 objectsof j this be if passed through-a conduit having a diametere of, the samesize as -the head portion. of the:

plunger;

Figure 6is-a cross-'sectional view-of a modificasl l tion of- -theplunger shown vain Figure '3 invwhich':i the skirt: portionof theplunger is extended bym the'addition of a cylindricalsleeve; t

Figure '7 is a cross-sectional view of a' -still:fur.-1li 131C131:modification'of the plunger showniin Figures: 3 and l 6 wherein-the;plunger is equippeds with a;

head. andxtail'portion-uand with alcenter skirt oril:

body portion disposed b'etweenithelhead and tall;

and,

Figure 8 is acrossesectional. View of ia'nealterl-s natel plungershowing.::.a head: and: skirt. cone. structed of different'materials. l

Inxthis inventiomwhich; as indicated'above; isl:

an. improvementiuponx-the-cycling gaslift:plunger; K

system, theproductionvand-apower tubing. strings;

are; of different-1nominal-internal1diameteri and the; gas i liftplunger: cycles; down-l: through; the: power tubingnndup:throughatheproductiontubs ing, The plunger providesiaa. seal." oredividem in 1theilarger: tubing-and preferablyseals bothk tub ing; strings :to-,preventfifiuid1from-,byepassing 171165,: plunger .ineither; strings-Ref erri ng news-specifics;

ally to Figures L and 2 foriamore-deta-tiled descrip" tion. of :the:invention;:a wellwis lequippedwithlaz i casingalflm'havinglatubingaheadigl l 1 Thisvtubinga.

head hasdzwo openings-I 2 and 3 whichyaresealedc as; by:weldinggaroundi: a' power tubing 1.4 and" ar:- production; tubing 15;;respectively-:1 .Bothap we tubingwl ligand productionztubingjstrin lizexten downintog-the-welland casing?! 0 tea depth gbel the workingfluid 1 levelagof the well- 1 Typi al the two'stringsextendltmtheiibottom ofrtheawell and are connectedcby a low-ent ced;|;5;:;f,ormin g as continuous, conduit within: they, well. At the;;,

. lower end of "the :tubing; 6 preferably int thew-head;

gas lift plunger for use in a, cycling gaszliftz; I

plims iv stem empl ng row r ubin ;andmrc:

ductiontubing of difierent sizes;

I h n u s. provided w tha el fiuidrin et 1 H. In some cases it isdesirable -;to use a stand s v 1ve I n he we l :fiuid nletqto' prev nt171K135; well .fiuids in. the conduit: from being; displaced acklitothew l w n re u e isan l l. the conduitto lift thewellfiuids it 'Ifhis;,sjzancl ing a ve maylbe-of ithe'remoyaple typ hat a e ed utt ush e-prm etub n. ac d: epa d; t; e i aied r e l i. ch: i l Qfi-ds heed-1 6'.niiiecn x ass o the; s

contour of the opening in the head may form part of the standing valvecage to facilitate removal of the standing valve. This perforated plateprevents plungers from falling into the standing valve opening in thehead and directs the plunger up the production tubing. In some cases itmay be desirable to leave out this perforated plate, and the system willoperate satisfactorily, since the plunger tends to follow the wellfluids around the U-bend in head l5 when standing valve i3 is used toprevent these fluids from flowing out through well fluid inlet 51. j

As disclosed in the above-mentioned copending application Serial Number261,714 Vincent,

it is generally desirable to place a constriction 2! near the lower endof the power tubing. This constriction, as explained in greater detailhereinafter, holds the plunger in the power tubin'g' as the gas pressureabovejthe constriction and plunger increases up to a predeterminedamount. By this means the lifting gas/oil ratio of the well may bedecreased. While our gas lift system which employs power tubing andproduction tubing of different sizes may be operated without theconstriction and retain some of the desirable characteristics of thesystem, we prefer such a constriction. This constriction is placed inthe power tubing several joints above the lower end, preferably at aboutthe working fluid level of the well. By this means the capacity of thecon duit below the working fluid level is increased. An orifice 22connecting the power tubing and the production tubing immediately belowthe com striction' allows the liquid level in both tubing strings toequalize, thereby additionally increasing the capacity of the conduitbelow the working fluid level so that more fluid can be lifted eachlifting cycle. The lower ends of power tubing I 4 and production tubingl5 thus provide an accumulation chamber 23 in which well fluidsaccumulate between cycles of the plungers. Other means for providing'alarge volume accumulation chamber are disclosed in the abovementionedcopending application Serial Number 261,714 and can be incorporated inthis system.

At the surface a plunger injector apparatus is provided to control theinjection of gas into the power tubing and to insert plungers into thegas stream as desired. The plunger injector apppa ratus also separatesplungers from the fluids pro- 1 duced from the well and reinjects theminto the power tubing. The upper end of the production tubing l5contains a U-bend 24 which directs well fluids and plungers down into aplunger hopper 25. The plungers may also be inserted into the hopper andwithdrawn therefrom through an opening 27 which is plugged with aremovable cap 28. The hopper 25 consists of a' perforated'tube 26 whichhas substantiallythe same internal diameter as'the nominal diameter of.the power tubing. This perforated tube has a flared top 29 which flts inriser 3i; Riser'iil has the same nominal diameter as production" flowline. The lifting gas may be separated from the well fluids in theseparator and the lifting gas may be returned to the well to bereinjected and lift additional well fluids. plungers in tube 26 isdriven down by the well fluids into a plunger injecting valve 35. ThisOne of the (iii valve comprises a long piston having a diametrical bore35. The plunger injecting valve is urged to the right, the closedposition, by a spring 37 so that the dia-metrical bore 35 is normally inregistry with perforated tube 26. When the valve is in thisnormal'position the gas inlet port 38 from gas supply line 39 is closedpreventing gas from entering the power tubing 14. When the plungerinjecting valve is in the left, the open positiorrthe diametrical bore36 registers with port'38 and power tubing I4 permittinglifting gas toflow from the gas supply line 39 into power tubing i4. As this valvemoves to the left it carries the bottom plunger ii in the plunger hopperwith it in the diametrical bore 36. When this bore is in registry withgas inlet port 38 the lifting gas in gas supply line 39 drivestheplunger into power tubing 5 l ahead of the lifting gas charge anddisplaces the plunger down the power tubing. j

The plunger injecting valve-is opened periodically by applying apressure fluid throughline d! .to the chamber 512. This pressure fluidthen acts on the valve head-43w displace the valve to the left. As thevalve is displaced to the left, the lower end of perforated tube 26 iscov ered by the long piston on the valve so that the plungers in thetube cannot move downwardly.

The valve is held to the leftagainst the force .of spring 37 by thecontinued application of pres-v sure in line ii until a predeterminedamount of gas pressure is built up inpower tubing I' l, untilapredetermined amount of gas has been injected time cycle injector. becontrolled by hand-operated'means or by any other means; When thepressure in line 4| 'is eventually removed; the valve returns toits nor:

mal or closed position causing diametrical bore 36 to register againwith perforated tube 26 and at the same time closing gas inlet port 38so that gas will not flow into power tubing 24. As

diametrical bore 35 registers with perforated tube 26 an additionalplunger is forced by the pro ducticn tubing pressure down intodiametrical bore 36. A perforation id may be provided in the valvehousing to-relieve the pressure in diametrical bore 36 so that'well'pressure will force the plunger into position. This perforation is thenclosed by the bottom plunger as' it comes into position so that we'llfluids are not wasted;

Obviously; the plunger injector and'the gas in jection may be controlledseparatelyas by providing a separate control valve on the gas supplyline 39 which may be opera'ted by these/me or:

some other control means.

In operation, gas supply line 39 is connected to a source of highpressure gas which maybe a high pressure gas well or a gas compressordis charge line. 'A number of plungers lil are then inserted into theplunger hopper through open ing 2? and the plungers ar'e forced down sothat the bottom plunger is lodged in diametrical bore 3d and the otherplungers are resting in series, one above the other, in perforatedtube'25. Pressure is then applied through line M to valve head 43displacing plunger injecting valve 35 to the left against compressionspring 37 and injecting the bottom plunger into the power tubing aheadof the gascharge as above described. The flow of gas through diametricalbore 36 which registers with gas inlet port 38, continues by holdingplunger injecting valve 35 in the left hand position 4 Referring nowtoFigures 4. and 5, the plungeriis' shown in its-deformed position whichis its condition as it is driven through the power tubing or the smallerof the two tubing strings. In this condition the skirt does not providea seal in the tubing but the head portion does since it has the 1 samediameter as the diameter of the smaller I tubing. That is, the skirtportion of the plunger is folded as shown in Figure and being folded itdoes not provide a continuous seal aroundthe outside with the inside ofthe small tubing. A modification of the plunger above described is shownin Figure 6. In this alternate embodiment the-head portion 53 iscylindrical, i. e., longer in the axial dimension of the plunger thanthe head portion of the plunger shown in Figure 3. This longer head issometimes desirable in order to keep the-plunger pr'operly oriented inthe pro-" duction or larger tubing string. The skirt 'of this plunger islike the skirt in the above-described embodiment except that it isextended by a sleeve 54which has an outside diameter substantiallyiequal to the maximum diameter of the skirt 5| and which is alsosubstantially equal to the maximum drift diameter of the larger tubingstring. This additional length of skirt is sometimes desired to reducethe slippage of well fluids past the plunger as the plunger is raisedthrough the production tubing. The maximum cross-sectional area of thecylindrical portion of the skirt on any plane perpendicular to the axisof the plunger is,

like the conical portion, less than the cross-sectional area string.

'Still another alternative plunger design is shown in Figure 7. In thisembodiment the plunger has a head portion 55 and a tail portion 56. Thediameter of the head and tail of this plunger embodiment issubstantially equal to the diameter of the smaller tubing. A" centralexpansible or body portion 51 of the plunger has an outside diametersubstantially equal to the nominal diameter of the larger tubing string.The

total cross-sectional area of the resilient material on any planeperpendicular to the axis within the central expansible portion is alsopreferably less than the cross-sectional area of the head or tail Thethin wallsof the central expansible portion form a cavity 58 whichportion of the plunger.

may be filled with air so that the outside diar'njeter may be variedsubstantially to accommodate,"

changes in the inside diameter of a conduit'. Al ternatively a passage59 may be provided through the tail portion 56 so that when the Plungeris placed in a well the cavity 58*bjecomes filled with well fluids. Byinserting this plunger'in the con tinuous conduit so that the tailportion 55 is 'exfi posed to gas pressure as the plungerrise's' throughthe production tubing, the pressure in cavity 5 8'] becom'es'greater dueto friction than the pressure on the outside of the body portion andthus this plunger produces a good seal with the inner surface of theproduction tubing and reducesthe by passing of well fluids around theplunger.

As indicated above, in the preferred embodiment, a constriction isplaced in the lower end of the power tubing so as to reduce the liftinggas/ oil ratio. However, this invention is not limited to the use ofsuch a constriction. Without a constriction it is sometimes unnecessaryto use a resilient material in the head portion of a plunger.

Sincethe power tubing and the. productiontubing are of different sizes,howeveiya means isprovidedfor a portion of the plunger to be expansible.As shown in Figure-8 a plungerfora oyof the opening in the'smallertubing power tubing.

cling gaslift plunger system may be made of a. 1 hardhead portion-6| andaresilient skirt:"'62'.z- The-head may be constructed of, for. example,-

wood, metal, or the like.v The skirt'which 18-1' silient,.as discussedabove, is then connected tothe head by any suitable means such as a bolt.63.

The skirt may be disc-like, as indicated, or it may be conical, asdiscussed above. The plunger .em-

bodiment, as indicated, is adapted for use normally only ina cycling gaslift plunger system which does not employ a constriction. It may be usedin a system employing a constriction provided the"- such as constrictionis made of resilient material synthetic rubber or the like.

From the foregoing it "can be seen that "we' have shown by variousexamples how a'cycling'" gas lift plunger system can be operated whenthe production tubing and power tubing are of differ-= ent-sizes. Asstated, it is often considered desir able for a number of reasons tousepower tubing-- and production tubing strings of different size. Inthe preferred embodiment this invention has been described withthelarger string generallyconstituting the production string. It will be apparent that in some cases the reverse might be preferred. Various othermodifications 'o'f-the apparatus and system of operation will beapparent to those skilled in this art. This inven tion should 'nottherefore be construed to be limited to the above description. It shouldbe limited only by the scope tubing extending into said well below theworking fluid level therein, said production tubing and;

said power tubing being of substantially different sizes, means at eachend for connecting saidpower tubing and said production tubing togetheras a continuous elongated conduit, 9. constriction said power tubing atabout said working fluid level of said well, an inlet for Well fluidsbelow said constriction for admitting well fluids intosaid conduitwithin said well, a standing valve in said inlet, a multiplicity ofplungers in said conduit.

a plunger injector for delivering said plungers in series into the upperend of said power tubing,

means to inject lifting gas into said power tubing:

behind each of said plungers and means at the upper end of saidelongated conduit forseparat-' ing said plungers from said well fluidsand discharging said well fluids from said conduit. I

2. A pump according to claim 1 in which said plungers comprise a'firstrelatively rigid part hav-' ing a diameter-about equal to the diameterof the smaller of said production tubing and said power tubing and asecond relatively flexible parthaving adiameter'about'equal to thediameterffof the larger of said production tubing and-said- 3. .Anapparatus according tubing togethen -an inlet for admitting wellfluidsof the appended claims. 1 We claim: V

1. A pump for lifting well fluids froma wel comprising parallelproduction tubing and power to claim 1 in'which the diameter of saidconstriction is in the range between about 0.5 and 0.9 of the nominaldiameinto said head, a standing valve in said inlet, plunger injectingmeans comprising hopper and valve means at the upper end of saidproduction tubing and said power tubing, said head and said plungerinjecting means connecting said production tubing and said power tubingtogether and forming a continuous elongated conduit, said hop per meansseparating said plungers from the well fluids and discharging said wellfluids from said conduit as said well fluids are lifted through saidproduction tubing by said plungers, said valve means being adapted toadmit lifting gas inter" mittently into said power tubing, and uponopening to discharge a plunger from said hopper into said power tubingahead of said lifting gas, and a multiplicity of said plungers in saidconduit, each of said plungers comprising a solid part having a diameterabout equal to the diameter of said power tubing and a skirt part havinga diameter about equal to the diameter of said production tubing.

5. In a cycling gas lift plunger pumping system for wells including aproducing tubing and a power tubing of different sizes connectedtogether at the bottom to produce a continuous conduit in a well, aplunger comprising a head having substantially the same diameter as thesmaller of said production tubing and said power tubing and a skirthaving substantially the same diameter as the larger of said productiontubing and said power tubing, said skirt being adapted to be deformed sothat it is as small as said head whereby said plunger may be cycledthrough said conduit and will seal both said production tubing and saidpower tubing.

6. In a pumping apparatus for wells including a production tubing, apower tubing, means at each end for connecting said production and saidpower tubing together as a continuous elongated conduit, an inlet forWell fluids at the lower end of said elongated conduit, 9, plungerinjector for delivering a series of plungers into the upper end of saidpower tubing, means for injecting lifting fluid behind each of saidplungers, and means at the upper end of said elongated conduit forseparating said plungers from said well fluids and discharging said wellfluids from said conduit, the improvements comprising production tubingand power tubing of different nominal diameters and a plunger having afirst part adapted to seal the smaller of said production tubing andsaid power tubing and a second part adapted to seal the larger of saidproduction tubing and said power tubing.

7. In an apparatus for gas lifting a well with plungers includingparallel production tubing and power tubing extending into said wellbelow the working fluid level therein, said production tubing beinglarger than said power tubing, means at each end for connecting saidpower tubing and said production tubing together as a continuouselongated conduit, a constriction in said power tubing, an inlet forwell fluids at the lower end of said elongated conduit, a plungerinjector for delivering a series of plungers into the upper end of saidpower tubing, means for injecting lifting fluid behind each of saidplungers, means at the upper end of said elongated conduit forseparating plungers from said well fluids and discharging said wellfluids from said conduit, and a cycling gas lift plunger comprising aresilient head having substantially the same diameter as said powertubing and a skirt having substantially the same diameter as saidproduction tubing, said skirt being adapted to be deformed to passthrough said power tubing and to expand and seal said production tubing.

8. A plunger for lifting well fluids in a well equipped with a cyclinggas lift plunger system having a relatively large production tubing anda relatively small power tubing comprising a cylindrical head having adiameter substantially equal to the nominal diameter of said powertubing and a skirt coaxial with the axis of said head and having adiameter substantially equal to the nominal diameter of said productiontubing, said skirt being adapted to be deformed to pass through saidpower tubing and to expand and seal said production tubing.

9. In an apparatus for lifting well fluids in a well equipped with acycling gas lift plunger system having a relatively large productiontubing and a relatively small power tubing connected together at bothends to form a continuous elongated conduit with well fluid inlet meansat the bottom and with well fluid discharge means and gas injectionmeans at the surface, said power tubing having a constriction near thelower end, a plunger comprising a resilient cylindrical head having adiameter substantially equal to the nominal diameter of said powertubing and a conical skirt, the apex of said skirt being connectedcoaxially to said head, said skirt having substantially the samediameter as said production tubing and being adapted to be deformed topass through said power tubing and to expand and seal said productiontubing.

LLOYD E. ELKINS. RENIC P. VINCENT. HENRY SCHAEFER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,790,450 Torrance Jan. 2'7, 1931 1,815,364 Ricker July 21,1931 1,932,497 Wellensiek Oct. 31, 1933 2,029,367 Geyer Feb. 4, 1936

